Recommended Practice - RP-01/02-10 Updated 5/2020 RETREAD AND REPAIR MATERIALS GLOSSARY OF TERMS ABRASION - The rapid wearing away of a tire in-service AUTOCLAVE - A heated pressurized vessel used for by scraping or rubbing. vulcanizing rubber products. ABRASION, SIDEWALL - An injury to the tire caused AWL - A pointed, round or flat tool used to probe by scraping or rubbing it against another material or punctures and/or other injuries. structure. AWLING - See VENTING. ACCELERATOR - A chemical that affects the rate of vulcanization of rubber compounds. BACKING - A removable protective material used on the application side of retread rubber and repair materials to ACTIVATOR - Chemicals added to rubber compounds preserve cleanliness and tackiness. to activate accelerators to speed up the vulcanization process. BALANCING - A process to correct for heavy or light areas of weight of a tire and/or tire/rim/wheel and wheel end ADHESION - Bond between two cured surfaces. assembly. ADHESIVE - See CEMENT. BALLAST - The addition of fluids inside a tire or external AFTER CURE - The process of cool down after the rubber weights applied to a vehicle to increase the load of drive product is removed from direct heat vulcanization. axles on vehicles. AGING - Evolution or change of physical and chemical BANBURY - An enclosed machine for mixing rubber and properties of rubber by oxidation, heat, operating compounds. stresses or moisture over a period of time. BAND LUGGING - A method of retreading earthmover AIR INJECTION - An inspection method using a high- tires using hand built-up extruded lugs and autoclave cure. pressure air probe to detect separation. BAR - Measure of pressure in international units. 1 AIR PRESSURE - Force exerted by air within a tire, bar = 0.9869 atm = 14.50 psi = 100 kPa. See USEFUL expressed in pounds per square inch (psi), kilopascals CONVERSION FORMULAS at the end of this document. (kPa) or bars. BASE WIDTH - A measurement of the width of the tread AIRBAG - An inflated flexible bag used to impart positive rubber which joins to the buffed surface of the tire. pressure on the article being vulcanized. BEAD - The anchoring part of the tire which is shaped ALIGNMENT - The requirement to have all wheels on to fit the rim/wheel; made of high tensile steel wires a vehicle running in the same direction. This is accom- wrapped and reinforced by the plies. plished by adjusting various parts of the vehicle’s suspension system to ensure proper handling stability BEAD AREA (Non-Repairable) - a specific measured and to minimize abnormal treadwear. dimension, based on a tire size, where an injury through the body ply material should not be repaired. These AMBIENT TEMPERATURE - Temperature (°F or °C) of dimensions are generally found on repair material manu- immediate surroundings, usually room temperature. facturers wall charts. ANTIOXIDANT - A chemical used to retard deterioration BEAD AREA COVERING - The outermost material protect- due to heat, light, oxygen or combinations thereof. ing the bead area while providing a tapered seat to fit the ARAMID - A class of heat resistant, high-strength rim configuration. synthetic fiber-type material used to form a ply cord. BEAD BUNDLE (Non-Repairable) - Central core of the ARC - See TREAD RADIUS. bead. A high strength, high tensile, brass plated carbon steel wire wound from a continuous strand into a high ASPECT RATIO - Ratio of the section height to the section strength unit. This major structural unit provides the width of a tire. anchor of the tire to the rim. ASYMMETRIC - A tread pattern or crown plies that differ BEAD CENTERING PLATE - An alignment device used to in aspect or construction between the outer and inner reduce tire diameter and center the casing in the retread shoulder areas of a tire. Such tires are directional. matrix. 1 RETREAD AND REPAIR MATERIALS GLOSSARY OF TERMS BEAD FACE/LEDGE/SOLE - The flat portion of the bead BEVEL CUT - An angle cut used on tread or other splices. between the heel and toe that contacts the rim/wheel. BEVELED SPLICE - An approximately 45° angle cut through BEAD FILLER - Sometimes called an “apex”, it is designed the gauge which allows the tread ends to diagonally to provide stiffness, stability, and durability in the bead overlap themselves. area. BIAS PLY (DIAGONAL PLY) - See TIRE, BIAS PLY. BEAD HEEL - The rounded portion of the bead that contacts the rim/wheel between the bead seat and BLADDER CURE - A method of shaping and curing a tire flange. using an expandable cylindrical rubber assembly. BEAD PLATE- Ring-shaped plates in molds which may be BLOW - A porous condition caused by a loss of pressure adjusted to alter the cross section of tires. or undercure. See POROSITY. BEAD REINFORCE - May be steel, fabric or a combination BLOW OUT - Rapid loss of air due to rupture. of reinforcing materials to give the bead stability and strength. See CHAFER. BLOW POINT - The curing time which is just less than that needed to develop a non-porous cure. BEAD SEALING AREA - The face/ledge/sole and heel of the bead that contacts the rim. With tubeless tires, the BLUE TRIANGLE - A bulge due to a section repair is bead seals to the rim and rim flange to retain air. allowed not to exceed 3/8” (10 mm) in height. This bulge may sometimes be identified by a blue triangular label in BEAD SEAT - The flat portion of the rim/wheel on which the immediate vicinity. the bead face/ledge/sole rests. BODY - Tire structure excluding tread and sidewall rubber. BEAD SEPARATION - Separation between components in the bead area. BODY PLY(IES) - Layers of rubber-coated parallel cords extending from bead to bead that encase both bead BEAD-TO-BEAD MEASUREMENT - The distance from the bundles and provide strength to withstand inflation heel of one bead, straight up at 90°, over the crown and pressures and tire dimensions. down the other side to a position on the heel of the other bead directly opposite the starting point. Measurement BODY PLY INSERT - An additional layer of rubber on top of is used before retreading to predetermine the correct the body ply to add to body ply durability. buffing dimensions, rubber size, and curing matrix to be used in the processing. BONDING - The joining of two materials by use of adhesives or vulcanization. BEAD-TO-BEAD RETREADING - A retreading process which includes veneering of the sidewall from the BRAND NUMBER - A number branded into one or both shoulder to the bead. sidewalls of a tire for identification purposes. BEAD TOE - The pointed part of the bead, opposite the BREAK - A surface opening and/or damage extending into heel, which faces the inside of the tire. or through the cord. BEAD WIDTH - Measurement commonly used for the BREAKER (BELT OR STRIP) - In bias/diagonal tires, a proper fit (bead spread) during buffing process. band or strip of rubber-coated bias-cut tire cord placed BEAD WIRE - See BEAD BUNDLE. circumferentially around the tire between the last ply of casing fabric and tread. Sometimes called the impact or BELT - A reinforced cord layer located circumferentially shock ply. around the tire and under the tread. BUCKLE - Tire distortion caused by improper molding, BELT EDGE FILLER - A special rubber covering over steel evidenced by wrinkling on the inside of the casing. belt edges to resist belt edge fatigue. BUFF CONTOUR - The specified shape of a buffed area. BELT EDGE INSERT - Helps optimize belt and body ply contours. BUFF(ING) - Removal of the previously vulcanized rubber surface. BELT OVERLAY - A reinforced fabric layer extending over the belts to reinforce the belt package. BUFF LINE - The dividing line in the cross section of a tire between the buffed surface of the original tire and the BELT SEPARATION - Separation of the belts from the plies new retread rubber. or tread, or from each other. BUFFED RADIUS - A measurement of the buffed surface BELTED BIAS - See TIRE, BELTED BIAS. curvature from shoulder to shoulder. 2 RP-01/02-10 RETREAD AND REPAIR MATERIALS GLOSSARY OF TERMS BUFFED SURFACE - A specifically prepared surface of a CARBIDE CUTTER / CARBIDE BURR - A rotary cutting tool. tire casing or repair area to provide proper texture to Carbide is a hard, metallic material. help promote adhesion to the new rubber. CASING - A used tire to which additional tread may be BUFFED TEXTURE - That surface produced by buffing, attached for the purpose of retreading. rasping or cutting. CASING DISTORTION - Processing defect in which the BUFFER - A machine used to rasp the old tread from the natural shape of the tire is deformed by constriction in casing. A powered rotary rasp provides a clean, even matrix during the retreading process. surface for adhesion of the new tread rubber. CASING PLY - See BODY PLY(IES). BUFFING TEMPLATE - A machined device of a specified shape used to obtain the required buffed radius. CAUTION - Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate BUILD-UP - Application of tread rubber or repair rubber injury; may also be used to alert against unsafe practices to a casing. (ANSI Z535.3, Environmental and Facility Safety Signs). BUILDER - A machine used to apply and stitch tread CEMENT - An adhesive rubber compound usually rubber to a casing. dissolved in solvent used to provide building tack and cured adhesion. May be brushed or sprayed on the buffed BULGE - A protrusion or raised area, usually in the tire surface. Some cements may be water-based. sidewall. CENTERLINE - Circumferential line at the center of the BUMPING - Opening and closing of mold to center a tire, tire’s crown area; aids in centering of the new tread. allow rubber to flow, and gases to escape.